1. Field of the Invention
This invention relates to a spoked wheel for a bicycle, more particularly to a spoked wheel with a plurality of spoke units that form coplanar planes.
2. Description of the Related Art
Referring to FIGS. 1 and 2, a conventional spoked wheel 100 for a bicycle having an axle defining an axis is shown to include an annular wheel rim 10, a wheel hub 20, and a plurality of spokes 30. The annular wheel rim 10 has a left annular rim wall 11 and a right annular rim wall 12 opposite to each other in an axial direction parallel to the axis of the axle. The left and right annular rim walls 11, 12 have a plurality of first mounting holes angularly displaced from one another about the axis. Moreover, the wheel hub 20 includes a left flange 21 and a right flange 22 opposite to each other in the axial direction. The left and right flanges 21, 22 have a plurality of second mounting holes angularly displaced from one another about the axis. The spokes 30 of a conventional spoked wheel 100 are hooked to the annular wheel rim 10 and the wheel hub 20 at corresponding ones of the first and second mounting holes. More particularly, the spoke 30A is connected to the left annular rim wall 11 and the right flange 22, while the spoke 30B is connected to the right annular rim wall 12 and the left flange 21. Furthermore, the spokes 30 have first bent portions 31, 32 which are inserted through the second mounting holes in the corresponding one of the left and right flanges 21, 22. The spokes 30 further have second bent portions 33, 34 which are inserted through the first mounting holes in the corresponding one of the left and right annular rim walls 11, 12.
The conventional spoked wheel 100 has several drawbacks. First, due to the spoke distribution, when under stress as shown in FIG. 3, there are situations where the forces are not fully counteracted by any spoke which would, consequently, cause an unbalanced feeling during riding. Second, due to the alternate spoke arrangement, a major portion of the force could not desirably propagate along the length of each of the spokes on which the force is applied. In other words, the spoke bracing effect is not maximized. Last but not least, the forces tend to focus on the bent portions of the spokes 30 where deformation or breakage of the spokes 30 or wheel rim 10 would easily occur. Thus, the rigidity of the annular wheel rim 10 in a direction radial to the axis is relatively poor.
The object of the present invention is to provide a spoked wheel for a bicycle with unbent spokes presented in pairs to increase the strength of the wheel and to balance the forces applied onto the wheel.
According to this invention, a spoked wheel is adapted for use in a bicycle which has an axle defining an axis, and comprises a wheel hub which has an inner hub wall surface adapted to be rotatably mounted on the axle about the axis, and an outer hub wall surface opposite to the inner hub wall surface in radial directions. The outer hub wall surface includes left and right surrounding ends opposite to each other in an axial direction parallel to the axis. Left and right flanges extend in radial directions respectively from the left and right surrounding ends, and terminate respectively at left and right surrounding edges which are spaced apart from each other in the axial direction. Left and right surrounding mounts extend in the axial direction respectively from the left and right surrounding edges, and have left and right sets of first anchored sites, respectively. Each of the left and right sets of first anchored sites includes a plurality of first anchored loci angularly displaced from one another about the axis. An annular wheel rim is disposed to surround the wheel hub about the axis, and includes an annular rim wall surrounding and facing towards the outer hub wall surface. The annular rim wall includes left and right annular wall portions opposite to each other in the axial direction. The left and right annular wall portions have left and right sets of second anchored sites, respectively. Each of the left and right sets of second anchored sites includes a plurality of second anchored loci which are angularly displaced from one another about the axis. Each of left and right sets of spokes has a plurality of spoke units. Each of the spoke units includes proximate and distal anchoring ends which respectively engage a corresponding one of the first anchored loci and a corresponding one of the second anchored loci to form a plane such that left and right planes respectively formed by a corresponding pair of the first anchored loci, a corresponding pair of the second anchored loci, a corresponding pair of the proximate anchoring ends, and a corresponding pair of the distal anchoring ends, are coplanar with each other.